Cellulose-ether composition



v Patented Dec,

rarest crates.

RAY L. STINCHFIELD, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTIKAN' KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

No Drawing. Application filed .Tune 8,

To all whom "it may concern:

Be it known. that I, RAY L. STINCHFIELD,

a citizen of the United States of America,

residing at Rochester, in the county of Monroe and State of New York, have in:

vented certain new and 'useful Improvements in Cellulose-Ether Compositions, of Which the following is a full, clear, and exact specification.

This invention relates to solvents for making strong solutions of Cellulose ether and also relates to the cellulose ether compositions produced by the aid of. such solvents. One object of my invention is to provide a solvent Which will dissolve such large proportions of cellulose ethers that thick or viscous fiowable solutions may be obtained for use in plastic and film making arts. An-

' other object of my invention is to provide a celludose ether solution which may be manufacturedinto strong, flexible, transparent film on the machines and-'byl'the methods now in use. In U. S. Patent No. 1,188,376,Lilienfeld,' June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are practically insoluble in water, and my invention relates but is not limited to the ethers having that property. While the ethers form thin solutions in benzol or methyl alcohol, it has been found that such single solvents by themselves do not dissolve a sufficient proportion of the ethers to make a desirably thick, flowable composition or dope, such as may be used, for instance, in the manufacture of photographic film base by the customary methods.

I have discovered that an. adequately strong and useful solvent may be prepared by mixing these substances. The proportions may vary very largely. I find, however, that the most useful range varies from a mixture of 90 parts of benzol with l0 parts of methyl alcohol by weight to 30' CELLULOSE-ETHER COMPOSITION.

1922. Serial No. 566,829.

parts of benzol and 70 hol by Weight. The latter mixture is the preferred one. The cellulose ether, such for example as Water-insoluble ethyl cellulose, may be dissolved in this mixture in any convenient proportion. For use in photographic film base manufacture, there may be used 1 part by weight of the ether to from 4 to 6 parts by weight of the mixed solvent. Neither to 6 parts by weight of methyl alcohol alone nor 4 to 6 parts by Weight of benzol alone will dissolve 1 part of this ether to form a flowable dope.

Other substances which impart suppleness, incombus'tibility, or other qualities to the film may be added to-the dope, such modifying agents being for instance triphenyl phosphate, tricresyl phosphate, camphor, Inonochlornaphthalene, etc. The ingredients are of the ordinary commercial type and sufficiently purified for the process of film manufacture, so as to parts of methyl alcogive a dope yielding films having the proper relative freedom from color. The viscousflowable' dope above described can be used in connection With the usual film-forming apparatus without the necessity of expensive alterations in the latter.

Having thus described my invention, What I claim as new and desire to secure by Letters Patent is:

1. Aviscous, flowable film-forming composition, comprising water-insoluble ethyl cellulose dissolved in a mixed solvent comprising approximately parts by weight of methyl alcohol and 30 partsof benzol.

2. A fiowable, film-forming composition, comprising cellulose ether dissolved in a mixed solvent comprising from 90 to 30 parts by weight of benzol and from 10 to 70 parts by Weight of methyl alcohol.

Signed at Rochester, New York, this 5th day of June, 1922.

a RAY L. STTNCHFIELD, 

